Kano: A suicide bomber killed four people and wounded dozens Sunday in an attack at a bus station in Potiskum, northeastern Nigeria, police and hospital sources said.

The town has come under frequent attack by Boko Haram militants and was the scene last Sunday of a bombing in a crowded market carried out by two female suicide attackers, one believed to be aged around 15.

A police officer at the scene of the latest bombing said four bodies and 48 injured people had been taken away.

The bomber "blew up his car at a bus station," said the officer, asking not to be identified because he was not authorised to speak to the media.

A nurse at the Potiskum General Hospital gave a similar death and injury toll, and said local residents had rushed to the hospital in search of their loved ones.

Brutal raids, massacres, suicide bomb attacks and kidnappings by Boko Haram have claimed at least 13,000 lives and driven an estimated 1.5 million people from their homes, mainly in arid northeast Nigeria.

Neighbouring Cameroon, Chad and Niger have launched a regional bid to combat the Islamists, as their attacks spread beyond Nigeria and concern mounts over the failure of Nigerian authorities to regain control.